Ummm ....... I think x=80
Answer:
a. 2x + 4
Step-by-step explanation:
Four more than twice a number
Let x = unknown number
Four more than twice of x
Twice of x can be written as 2x
Four more than 2x
Four more can be written as + 4
We get 2x + 4
No wonder you have posted this. It is not easy. Scale is a straight line measurement. You need to use a side of a square.
Left: 1 side of a square = 1 meter.
Center: 3 tops of a square = 1 meter.
Therefore 1 side of a square = 1/3 of a meter.
Right: 1 side of a square = 0.5 meters.
We have


425 corresponds to a z of

575 corresponds to

So we want the area of the standard Gaussian between -3/4 and 3/4.
We look up z in the standard normal table, the one that starts with 0 at z=0 and increases. That's the integral from 0 to z of the standard Gaussian.
For z=0.75 we get p=0.2734. So the probability, which is the integral from -3/4 to 3/4, is double that, 0.5468.
Answer: 55%